I was down at Shakespeare raceway this weekend and it looks like I've bent a valve. I got the start all wrong and the revs went through the roof and it broke still did a 15.5 though. We've done a compression test there and cylinder 1 shows 0psi the others are fine. I'll take the head off sometime and have a look.
I'm going to do most of it myself so i'll probably be asking loads of questions when it comes to putting it back together ???
That's a pain in the arse mate, was 15.5 your best run of the day or did you get lower?
Hope you can get it sorted soon.
No best was a 15.0@97mph. It was going quite well, reckon I could've gone faster too
argh!
what do you reckon happened then, valve float or slipped cam belt or something else? What's your rev limiter set at?
Not sure whats happened, cambelts not slipped. Rev limits 8k but i never usually go above 7k apart from this time by accident. Once it's all sorted I want to try and get the rev limit lowered which I was thinking of doing anyway.
Quote from: SteG40 on April 20, 2009, 01:22:12 PM
No best was a 15.0@97mph. It was going quite well, reckon I could've gone faster too
sounds like you were struggling for traction as you got a not bad terminal speed but slow 1/4 mile time.
i got 14.7 in my G when it was running only 150bhp with 175/50/13 tyres!
Yeah thats Spot on Robin, I can't get the thing off the line. I need to get my diff fitted that should help.
I did a 14.0 @ 99mph running about 170bhp on 175/50 R13 tyres. Suspension (inc. geometry setup) and tyres can make a huge difference to your time.
Ste - I can edit your map to lower the rev limit if you want. It's something I did on mine when it was still running Digifant after Steve mapped it, went down to 7000rpm.
When you pull the head off, check the valve guides for wear. I had a big valve head that ate the guides in under 3,000 miles, wondering if your guides have done the same, culminating in mashing one a valve up as they rattle around at high rpm.
Having said that, wasn't your car breathing a lot of oil? May well be more bottom end related?
That would be brilliant if you could do the rev limit Andy.
I'll check the guides once the heads off, it was breathing alot but i'm putting that down to a blocked breather were pretty sure it's a valve thats gone.